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Products => Other Equipment & Products => Topic started by: Kiriakos-GR on August 25, 2010, 03:50:21 pm

Title: Ultrasonic Distance Measurer DM220
Post by: Kiriakos-GR on August 25, 2010, 03:50:21 pm
Today I got my Ultrasonic Distance Measurer DM220 ,
I had selected it, very carefully , got very impressed of the large dual lines display,
Plus the price , that was just a bit higher than the ultra cheap ones. ( Ebay )

The manufacturer brand name is missing, and I was a bit skeptic for few minutes,
after testing it , by making lots of measurements , and verifying the results with an tape meter ,
now I can proudly show-of a bit , about it ..     ;D

Its big in size as device ,  but it is so , because in some measurements it must stand alone in the ground.

I scanned the tiny in dimensions Users manual , so to be able to read it ..

What I liked most as function , is the one that you can take multiple measurements,
and its one are added at the total length. 

My need was to be able measure in door , and find out the  length of the cables that I need, so to run across the room , vertical or horizontal .

Great device , accurate ,  a bit bulky , easy to read , many options.
Easy to use ,  but some training cycle is needed , so to learn how to place it correctly in the space for proper measurements. 

Pictures .. 

Title: Re: Ultrasonic Distance Measurer DM220
Post by: Kiriakos-GR on August 25, 2010, 03:52:20 pm
Users manual

Title: Re: Ultrasonic Distance Measurer DM220
Post by: Kiriakos-GR on August 26, 2010, 07:08:46 pm
Today I got this meter at the factory that I currently work,
For further extreme testing.

In there, there are lots of  big and tall buildings ,
so it was  an large scale test area ..

Just one of the 8 major “ work shops “ in it .
Its   80 meters  long  ,  25 meter wide , and 16,34 meter tall .. (crane bridges moving around in it)  

Well  I have mixed feelings , about my findings ,
As I discovered the true capabilities of those ultrasonic devices.

This technology  are based  on sound ,  the device its an sound source of 40KHz ,
The returning  “ reflected “  sound , it’s the measured  portion.

But the “ reflected “  sound  ,  in order to be reflected , it must hit  on something that reflects  the sound back .

So I tested the meter on several type of surfaces .
And found the limits .

The good part about the meter , are that if it did not gets an specific amount of reflected sound ,  it does not give an reading at all .

So  there is less chance to get an false measurement , at the worst scenario ,
You will get an   “ error  “  message from the device , and no numbers.

And now the data of my tests .

1)  Perfect finished wall and painted  =  19.90 meters   Max detectable distance.
2)  Metal large doors  - full metal surface  =  11 meters   Max detectable distance.
3)  Wall  covered with tiles  =   The most lovable  surface for measurements by the. meter … my testing area was  like  12 x 12 meters , and as I said the meter loved the tiles .
5)  Wall with common red bricks =  10 meters  Max detectable distance.
6) Wall  with  covered with plaster ,  but with the technique of  “  Sprayed  plaster ,
By  machine …. Its full of uneven spots , looks like an sponge , and it was the worst material  for this meter ,  the detected distance dropped to just  7 meters .

Extra remarks …

This meter are suggested to be used at fresh finished buildings,
That they are still totally empty  ( no furniture ).

When the measured space has objects in it ,  you must do several testing measurements, so to find the most clear  optical line , across the room.  

The only fool proof measurement with it , are the distance between the floor and the ceiling .
But for my taste , it’s the most important than all ,  and the most hard to make with any other alternative way !!  

So ,  now with all this new details in mind  , I continue to give to it,
my thump up.
Because,  at the end of the day ,  it will do what it promises .

One last thing that impressed me ,  was that  if you step  at the center of the measured area ,  you can measure  on an average rate   about 15 meters in front of you ,
And by turning your body  180 degrees another 15 meters at the back .
So  you can do safe measurements with out the assist of an second person  ( tape meter) , Up to 30 meters .        

And with the same  technique  ( front + back) , even at the worst surface like  the spayed plaster ( material cement ) ,  there is 14 meters of measured distance.

I had one conversation on the job, about alternative “distance measuring systems” with laser pointers.

Well, they do exist .
But , how they will measure anything .... at out-door ...  with a bright sun light ?   ;)

The ultrasonic meter did not care about the sun light,
and it offered reliable hand held measurements ,  with out tripod on daylight .    

Conclusion … If there is an silent battle, between ultrasonic VS laser,
Both contesters haves their weak points.  

Title: Re: Ultrasonic Distance Measurer DM220
Post by: Kiriakos-GR on August 26, 2010, 07:28:34 pm
And the last part of this review ..

Battery consumption ..

The meter uses one 9 Volt battery .

When it powered up ,  it uses 8mA as consumption .
Its measurement  lasts for 3 seconds ,
And It draws  as 19mA  , and then falls back to 8mA .

It has an auto power-off  function , 
And  at this mode , my analog   multimeter Goerz Metrawatt  at the 2.5mA range was unable to detect any current at all  !!
So I conclude that by keeping the battery always connected ,
There is no danger to find it empty, even at long periods of storage.